This invention relates generally to an ink ribbon cartridge of the type used in printers and typewriters and more particularly to ink ribbon cartridge providing a continuous loop of ribbon which feeds out from one side of the cartridge and returns to the cartridge after being used for printing. In ink ribbon cartridges of the prior art, there are problems, for example, a spot of printed matter appears unintentionally at the time of printing characters on a recording paper because the ink ribbon has become creased and wrinkled while stored in the cartridge case. Further, if the ink ribbon is stored in small folds or loops, the quantity of ink ribbon which can be stored in a case becomes small and it is necessary to enlarge the case to obtain storage for the required length of ink ribbon. Such problems can be resolved if the ink ribbon is stored in the case in an orderly fashion and the folds or loops in the ribbon are large.
In the prior art a rubber band is attached to the feed roller and pinch roller between which the ink ribbon is positioned. This helps to overcome the storage problems described above. However, such an ink ribbon cartridge mechanism has several disadvantages related to the characteristics of control provided by the rubber band, the increase in the number of production steps for inserting and attaching the rubber band to the feed roller and the pinch roller, the need to control the force applied by the rubber band to the feed roller and pinch roller, and so on. These added difficulties raise questions of product reliability and also increase the cost of production.
What is needed is an ink ribbon cartridge which stores a large quantity of ribbon in a relatively small case and transmits the ribbon for printing without wrinkles which can cause the printed matter to be marred in appearance.